Apparatus and method for highly controlled electrodeposition

ABSTRACT

An apparatus and method for highly controlled electrodeposition, particularly useful for electroplating submicron structures. Enhanced control of the process provides for a more uniform deposit thickness over the entire substrate, and permits reliable plating of submicron features. The apparatus includes a pressurized electrochemical cell to improve plating efficiency and reduce defects, vertical laminar flow of the electrolyte solution to remove surface gases from the vertically arranged substrate, a rotating wafer chuck to eliminate edge plating effects, and a variable aperture to control the current distribution and ensure deposit uniformity across the entire substrate. Also a dynamic profile anode whose shape can be varied to optimize the current distribution to the substrate. The anode is advantageously able to use metallic ion sources and may be placed close to the cathode thus minimizing contamination of the substrate.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of the filing of U.S.Provisional Patent Application Ser. No. 60/431,315, entitled “Solid CoreSolder Particles for Printable Solder Paste”, filed on Dec. 5, 2002,U.S. Provisional Patent Application Ser. No. 60/447,175, entitled“Electrochemical Devices and Processes”, filed on Feb. 12, 2003, andU.S. Provisional Patent Application Ser. No. 60/519,813, entitled“Particle Coelectrodeposition”, filed on Nov. 12, 2003. This applicationalso is a continuation-in-part of U.S. patent application Ser. No.10/728,636, entitled “Coated and Magnetic Particles and ApplicationsThereof”, filed Dec. 5, 2003. The specifications of each applicationlisted are incorporated herein by reference.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention (Technical Field)

[0003] The present invention relates to an apparatus and method forelectroplating substrates or other objects, particularly semiconductorwafers. The present invention can also be used to plate ceramic panelsused in thin or thick film type packaging, as well as anti-reflectivecoatings of lenses and other types of glass substrates. The apparatusmay also be used for microvia deposition, wafer bumping, and flip chipbumping. The apparatus provides for a much higher control of thedeposition parameters, enabling fine submicron features to be plated.The invention also relates to an anode for electrochemical processeswhose profile can be varied to any desired shape. The anode may be usedwith metallic ion sources without contaminating the substrate.

[0004] 2. Background Art

[0005] Note that the following discussion is given for more completebackground of the scientific principles and is not to be construed as anadmission that such concepts are prior art for patentabilitydetermination purposes.

[0006] A traditional electroplating cell comprises a tank to hold thechemical solution, one or two anodes that are either of a solublecomposition of the metal to be deposited or insoluble platinumizedanodes. The item to be plated is mounted horizontally on the cathode, ata gap of approximately four inches from the anode(s). A DC power supply,operating with either a constant, switched or pulsed output, with anoptional periodic polarity reverse is most often utilized in currentcells. Configurations of this type do not provide sufficient controlover the deposition process to enable the uniform plating of submicronfeatures on a substrate. Nor can the operating geometries and otherparameters of the cell be easily varied to accommodate different typesof plating substrates or patterns, or to adjust the plating conditionsto ensure uniformity and quality of the deposit.

[0007] It is known in the art to enhance the deposit uniformity byintroducing an aperture to selectively mask off the edges of thesubstrate. However, when plating submicron structures it is criticalthat the size of the aperture be adjustable to more precisely controlthe thickness uniformity, whether before or during processing. Inaddition, an adjustable aperture enables the cell to be used formultiple types of deposits, reducing the capital equipment requirementsof the user, and minimizing contamination by avoiding transfer of thesubstrate from one cell to another.

[0008] The use of shaped anodes to improve deposit uniformity andefficiency are also known in the art. However, the optimal shape dependson the particular electrochemical process and the characteristics of thepattern on the substrate, among other things. Thus there is a need foran anode with variable shape capabilities.

[0009] Another drawback of the existing art is that in order to placethe anode close to the cathode, an insoluble anode must be used with ametal salt solution, which is inferior to a metallic ion source.Alternatively, a soluble metallic anode may be used, but it cannot beplaced close to the cathode because of potential contamination. Inaddition, as the anode dissolves it changes shape, reducing the verycontrol of the deposit parameters that was provided by choosing theinitial shape of the anode. Accordingly, there is a need for aninsoluble anode that can use metallic ion sources and that be placedclose to the cathode.

SUMMARY OF THE INVENTION (DISCLOSURE OF THE INVENTION)

[0010] The present invention is of an apparatus for electrochemicaldeposition on a substrate such as a wafer, the apparatus comprising ananode, a cathode with a vertical mounting surface, a pressurized cell tocontain electrolytic solution, and an aperture disposed between theanode and cathode; wherein a vertical flow of the electrolytic solutionis substantially laminar in a vicinity of the cathode. The apparatusoptionally comprises a reservoir, which preferably forms a closed,filtered system with the cell. At least one filter is preferably asubmicron filter.

[0011] The wafer may optionally be coated so that only certain features,such as submicron features, on the wafer receive the deposition.

[0012] The cell is preferably pressurized to at least approximately oneatmosphere above ambient pressure, and optionally is pressurized to atleast approximately two atmospheres above ambient pressure. The cathodepreferably rotates about a horizontal axis perpendicular to saidmounting surface. The cell preferably has a geometry that facilitatessaid laminar flow, for example comprising an inverted triangular orconical shape in a vicinity of an electrolyte inlet port. Additionallythe cell is preferably of sufficient height to ensure that said flow islaminar in a vicinity of said cathode.

[0013] The aperture is preferably electrically insulating, andpreferably comprises a circular opening which is variable in size,optionally during operation of the cell. The aperture preferablycomprises an iris with at least three paddles. The opening is preferablycontinuously variable from a size larger than the size of the substrateto completely closed.

[0014] The anode is preferably situated less than approximately 5 cm,more preferably less than approximately 1 cm, and most preferably lessthan approximately 0.5 cm from the cathode. The metal ion source ispreferably situated behind the anode, thereby minimizing contaminationfrom reaching the substrate while the anode retains a constant surfaceprofile. The surface profile of said anode is preferably controllablyvariable, and may be varied during operation of the cell. The anodepreferably comprises parallel hollow electrically conducting tubes.

[0015] The apparatus may optionally comprise a magnet, such as anelectromagnet or at least one permanent magnet. The magnet preferablyprovides for the codeposition of magnetic particles along with theelectrochemical deposition on the substrate. The codeposition may occurbefore, during, and/or after the electrochemical deposition. Thestrength of the magnet is preferably adjusted to provide a desiredconcentration of magnetic particles on the substrate.

[0016] The invention is further of an apparatus for performing multipleelectrochemical depositions on a substrate, the apparatus comprising ananode having a variable surface profile, a cathode with a verticalmounting surface, a pressurized cell to contain electrolytic solution, aclosed, optionally filtered system for circulation of the solution, andan aperture with a variably sized opening disposed between the anode andthe cathode; wherein a vertical flow of the electrolytic solution issubstantially laminar in the vicinity of the cathode. The multipledepositions are preferably carried out without opening the cell betweeneach deposition, even though the surface profile of the anode and/or thesize of the opening are preferably controllably varied as desired foreach deposition.

[0017] The invention is also of a method of electrolytically depositinga material on a substrate, the method comprising the steps of providingan electrolytic cell, providing an anode, mounting the substrate on acathode so that a surface of the substrate is vertically disposed,disposing an aperture between the anode and cathode, providing laminarflow of electrolyte solution through a cell, pressurizing the solutionto a desired pressure, and providing an electric potential differencebetween the cathode and the anode. The solution is preferably filtered.Optionally, submicron features on the substrate are uniformly plated.The substrate is preferably rotated about a horizontal axisperpendicular to the surface, and the aperture preferably has a variablesize opening.

[0018] The method preferably comprises situating the anode less thanapproximately 5 cm, more preferably less than approximately 1 cm, andmost preferably less than approximately 0.5 cm from the cathode. Theanode is preferably situated between a metallic ion source and thecathode and preferably minimizes contamination from reaching the cathodewhile retaining a constant surface profile. The surface profile of theanode is preferably controllably varied as desired. Optionally amagnetic field is provided to codeposit magnetic particles with thematerial on the substrate. The magnetic field is preferably varied toadjust the composition of the magnetic particles on the substrate.

[0019] The invention is further of a method of performing multipleelectrolytic depositions on a substrate, the method comprising the stepsof providing a pressurized electrolytic cell, providing an aperture witha variably sized opening, optimizing deposition parameters of the cellincluding a pressure of the cell and a size of the opening for a desireddeposition, depositing a material on a substrate; and repeating theabove steps without opening the cell.

[0020] The invention is also of an anode for use in an electrochemicalprocess, the anode comprising a plurality of parallel hollowelectrically conducting tubes with sides in slideable contact with oneanother and a clamp circumferentially disposed around the plurality oftubes to prevent motion of the tubes. The tubes are preferablycylindrical or have a cross section comprising a regular polygon. Thesurface profile of the anode preferably comprises the positions of theends of each of the tubes which face the cathode. The anode's surfaceprofile is preferably adjustable by sliding the tubes relative to oneanother, and preferably comprises a flat, convex, hemispherical,conical, domed, curved, or pyramidal shape.

[0021] The anode preferably comprises an electrically conductingmaterial, which may be soluble, or preferably insoluble, for exampleplatinumized. The anode preferably comprises a receptacle for placementof an electrochemical ionic source media, preferably a metallic ionsource, on the side of the anode opposite the surface profile. The anodeminimizes contamination from reaching the cathode while retaining aconstant surface profile. The anode is preferably used in any of thefollowing processes: plating, electroplating, electrodeposition,chemical and mechanical polishing (CMP), electropolishing, etching, orelectrolysis.

[0022] Objects, advantages and novel features, and further scope ofapplicability of the present invention will be set forth in part in thedetailed description to follow, taken in conjunction with theaccompanying drawings, and in part will become apparent to those skilledin the art upon examination of the following, or may be learned bypractice of the invention. The objects and advantages of the inventionmay be realized and attained by means of the instrumentalities andcombinations particularly pointed out in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings, which are incorporated into and form apart of the specification, illustrate several embodiments of the presentinvention and, together with the description, serve to explain theprinciples of the invention. The drawings are only for the purpose ofillustrating a preferred embodiment of the invention and are not to beconstrued as limiting the invention. In the drawings:

[0024]FIG. 1 is an exploded view of a preferred embodiment of theelectrodeposition apparatus of the invention;

[0025]FIG. 2 is an isometric view of the cell and reservoir;

[0026]FIG. 3 shows a cross section of the cell;

[0027]FIG. 4 depicts a close up of the cross section of the plating areaof the cell;

[0028]FIG. 5 shows the chuck in position for wafer loading or unloading;

[0029]FIG. 6 shows the wafer in the loaded position;

[0030]FIG. 7 shows the chuck rotated to the vertical position;

[0031]FIG. 8 shows a cross section of the wafer chuck;

[0032]FIG. 9 is a detail of the rotating wafer mount;

[0033]FIG. 10 is an isometric view of the rear of the chuck, showing therotation mechanism;

[0034]FIG. 11 is a cutaway view of the cell depicting the iris fullyopen;

[0035]FIG. 12 is a cutaway view of the cell depicting the iris partiallymasking the substrate;

[0036]FIG. 13 is a cutaway view of the cell depicting the iris fullyclosed;

[0037]FIG. 14 shows an isometric view of one embodiment the dynamicprofile anode assembly;

[0038]FIG. 15 shows an exploded view of the dynamic profile anodeassembly;

[0039]FIG. 16 shows a top view and cross section of the dynamic profileanode assembly depicting a convex surface profile;

[0040]FIG. 17 depicts the dynamic profile anode and clamp showing aconvex surface profile;

[0041]FIG. 18 is an exploded view of FIG. 17;

[0042]FIG. 19 is a cross sectional view of a second embodiment of thedynamic profile anode with a flat surface profile;

[0043]FIG. 20 is a cross sectional view of the dynamic profile anodewith a convex surface profile;

[0044]FIG. 21 is a cross sectional view of the dynamic profile anodewith a conical surface profile;

[0045]FIG. 22 is an isometric view of the dynamic profile anode andanode diaphragm showing the conical surface profile;

[0046]FIG. 23 shows a cross section of the wafer chuck comprising anelectromagnet; and

[0047]FIG. 24 shows a schematic of the cell of the present inventionconfigured to provide co-deposition of magnetic particles.

DESCRIPTION OF THE PREFERRED EMBODIMENTS BEST MODES FOR CARRYING OUT THEINVENTION

[0048] The present invention is of an apparatus and method for highlycontrolled electrodeposition, particularly useful for electroplatingsubmicron structures. Enhanced control of the process provides for amore uniform deposit thickness over the entire substrate, and permitsreliable plating of submicron features, for example those on asemiconductor wafer. A primary advantage of the invention is that thekinetics of the cell, which are based on the geometries of the cell, canbe changed quickly to optimize plating on the substrate surface, for alldeposits including very thick film deposits and thin film deposits.

[0049] As used throughout the specification and claims, “substrate”means any substrate, wafer, lens, panel, and the like, or any other itemwhich is to be attached to an electrode to be plated. Such substrate maycomprise any material such as a semiconductor, including but not limitedto silicon, gallium arsenide, sapphire, glass, ceramic, metal alloy,polymer, or photoresist.

[0050]FIG. 1 depicts an exploded view of a preferred embodiment ofelectrodeposit cell 10 of the present invention comprising bulkhead 24and bulkhead door 26. Substrate chuck 12 is rotatable using pivotassembly 14 and slides on guide rod 16 to seal against the opening inbulkhead door 26. Aperture 18 is located between bulkhead 24 andbulkhead door 26, and is operated using stepper motor 20 which drivesbelt 22.

[0051] Referring to FIG. 2, reservoir 30 is where filter 34 and pump 32are preferably mounted, as well as instrumentation for controlling thecharacteristics of the electroplating solution or electrolyte that isintroduced into the WAVE Cell, such as temperature, pH, andconcentrations of metal species and other electrolyte components. Thisensures that all electrolyte characteristics are maintained at anoptimal level. Any type of brightener system may also be checked. Allchemical maintenance is preferably carried out in reservoir 30.Optionally, rather than being a standalone unit, the reservoir may beintegral with the cell itself. The electrolyte solution is pumped intocell 10 through solution inlet 36. Pressure valve 38 regulates thepressure in the cell, as more fully described below, and controls thecirculation of the electrolyte solution back to reservoir 30.

[0052] Unlike traditional electroplating devices, the entire circulationpath of the solution, and the process environment in which the wafer isplaced, is preferably enclosed, and more preferably comprises at leastone filter, including but not limited to a submicron filter. Thus theelectroplating environment is equivalent to a clean room, withoutrequiring the latter's expense, and ensures a reliable anduncontaminated deposit process.

[0053] As shown in FIG. 3, connected to the cell's cathode willpreferably be the negative terminal 40 of a DC power supply, operatingwith either a constant, switched or pulsed output, or with optionalperiodic polarity reversal, and connected to anode 100 will preferablybe the positive terminal 42 of the power supply. FIG. 4 is an enlargeddetail.

[0054] Chuck 12 is preferably comprised of articulating door 44 that canbe opened and can interface with automation known in the art formounting and dismounting of the substrate, permitting automatedsubstrate loading and unloading. As shown in FIGS. 5 and 6, substrate 50is mounted on chuck 12, which is preferably in the horizontal position.Chuck 12 holds substrate 50 on a flat surface and supplies the cathodiccurrent to the surface of substrate 50 via at least one contact 52. Thuschuck 12, and more specifically substrate 50, acts as the cathode in thepresent system, and the terms are used interchangeably herein. Cell 10of the present invention is capable of handling substrates in a largesize range, such as wafers used in the semiconductor industry, includingbut not limited to those from 75 mm to 300 mm in diameter. Optionally,the edges of the substrate may be masked by a grip ring, preferablycomprised of both metallic and insulating materials, that will supplycurrent at the edge of the substrate while masking the edge of thecurrent contact itself so that unnecessary deposits don't occur on thecontact. FIG. 7 shows door 44 rotated into the vertical position aboutpivot assembly 14 so it is ready to slide along guide rods 16 and sealthe opening in bulkhead door 26.

[0055] Chuck 12 is preferably rotatable, which provides advantages inuniformity of deposit that are described more fully below. Various viewsof the rotation mechanism are presented in FIGS. 8-10. Motor 58,optionally mounted on motor mount 66, is preferably used to provide suchrotation, connecting via gear 64 or other rotation transfer means, suchas a belt, to rotating shaft 62 that protrudes through o-ring seals 60in articulating door 44. A DC current is preferably fed through shaft 62via negative terminal 40, which will continuously supply cathodiccurrent during the process run. Once door 44 is closed, it canoptionally be fastened with bolts around the perimeter of the door andsealed by compressive-type gasketing 46.

[0056] The electrolyte, or plating, solution is then circulated into thecell, preferably entering from the base of the cell via solution inlet36. A process controller will preferably continue the circulation of theelectrolyte through the system until the desired thickness has beendeposited. Typical process steps for operating the present cellpreferably comprise a first rinsing, pretreatment with an activatingacid or cleaner, a second rinsing, electroplating, and a final rinsing.Optionally, post-treatment operations for sealing or for mask orphotoresist removal may be performed.

[0057] The pressure of the solution in cell 10 is regulated by pressurevalve 38 or other type of pressure regulator, which preferablypressurizes the cell to one or two atmospheres above open cell, orambient, pressure. However, any pressure may be utilitzed. For example,valve introduces back pressure into the cell, which optionally ismonitored and controlled by a pressure gauge or other controller. Theability to pressurize the cell provides control over pressure dependentcharacteristics of the plating process, for example deposit kinetics,which results in improved performance and an improved deposit.

[0058] Controlling the pressure in the cell also improves solutionexchange and ion supply on all surfaces of the wafer, including deepfilled vias and planer surface areas. In addition, pressurization of thecell provides a high efficiency of deposition at lower currentdensities. Existing electroplating systems are not able to electroplatesubmicron structures in part because the mass transfer of ions from theanode to the cathode has been incompatible in terms of the scale of thepattern that is built up on the surface of the wafers. According to thepresent invention, using lower amperage densities, optionally combinedwith switching the current on and off, enables finer control of thedeposit parameters. Thus submicron structures can be successfullyelectroplated and nanoscale vias can be filled uniformly, makingelectrolytic processes such as electroplating a viable alternative to anangstrom scale process like sputtering or vapor deposition.

[0059] Pressurizing the cell will also suppress the formation of gasessuch as hydrogen at the deposition interface, (i.e. the cathode, orsubstrate, surface). These gases cause undesirable porosity or voidsresulting in micropittings that typically occur in a deposit on thesurface of the cathode. Gases such as hydrogen also may reduce themechanical strength of the deposit; if hydrogen is left in the boundaryarea, brittle deposits or highly stressed deposits may be formed,resulting in tensile failure and possibly the deposit peeling back fromthe substrate. The integrity of the bond of the deposit, such as ametallic interconnect, to the substrate or wafer is critical to assurethe high reliability necessary for electronic components.

[0060] For applications in the submicron range, particulates, pores, andmicropittings that would normally be acceptable in traditional platingapplications are not tolerable because of the small size of the featuresto be plated as well as the required thinness of the deposit. Thus theoverall control of micropittings is of paramount importance ifsemiconductor wafers are to be electroplated. By using pressurization tominimize gas formation, the integrity of the initial deposit on thesurface of the wafer (when the voltage or the potential is at itshighest), which creates the first boundary layer between the substrateand the metal being deposited, will be greatly improved. This results ina surface morphology of sufficient quality to successfully platesubmicron structures.

[0061] The vertical configuration of the preferred embodiment of cell 10also helps to reduce the presence of undesirable gas and gas bubbles atthe surface of substrate 50 due to the laminar flow of electrolyte pastthe surface, which acts together with gravity to remove the gas upwardaway from the interface area of the substrate. The electrolyteoptionally passes through baffles which distribute the pressure withinthe solution and help create laminar flow. Laminar flow formation isalso preferably promoted by utilizing a non-rectangular shape of cell 10adjacent to solution inlet 36, preferably a triangular or conical shape,as shown in FIG. 1. The length of cell 10 is long enough to transformthe turbulent flow of the plating solution when introduced in the baseof the cell to a laminar flow as it passes the surface of the wafer. Thepressurization of the cell contributes to shortening the overall lengthof the cell required to achieve the laminar flow.

[0062] Laminar flow also enhances the plating solution by continuouslyand uniformly supplying solution of the optimum temperature and pH andion species to the substrate. By sweeping out gases and supplying acontinuous, reliable supply of electrolyte to the substrate, a morerobust and uniform deposit is achieved, allowing for a greater range ofchemical compositions for high-throw or low-throw baths to be utilized,giving the chemical process engineer more latitude. If laminar flow isnot present, a defect or non-uniformity of the deposit's thickness ormechanical properties may result.

[0063] The present invention also comprises further multiple means togreatly enhance the uniformity of the thickness of the deposit onsubstrate 50. The thickness can be kinetically controlled across theentire substrate by rotation of substrate 50 as described above, and byselective masking of the substrate's exposure to anode 100, whichtechniques serve to provide a far more uniform current density at allpoints on substrate 50.

[0064] In the present invention substrate 50 is preferably mounted onrotating chuck 12 comprising the cathode. Thus the leading edge ofsubstrate 50 with respect to the directional flow of the platingsolution, which ordinarily will develop a thicker deposit than the restof the substrate, is continually changed, distributing the mechanicalforces on the substrate's edge as well as leveling out the thickness ofthe plating at the edge, making it more consistent with that at thecenter of the substrate.

[0065] Another cause of thickness nonuniformity in a traditionalelectroplating cell, the “dog bone” effect, occurs because currentdensities are higher at the edges of the cathode or substrate, meaningthat the deposit will have a greater thickness there. By using anelectrically insulating aperture, or masking device, the center of thesubstrate, where current densities are the lowest, receivespreferentially higher exposure to the current, and the edges of thesubstrate, where the amperage densities are highest, is masked off fromthe current. The thickness of the deposit is thus more uniform acrossthe entire substrate. Although masking is known in the art, only fixedapertures have been utilized.

[0066] The present invention comprises an adjustable aperture 18,preferably comprising an iris mechanism, which enables variation of theiris size from all the way open (exposing the whole wafer) (FIG. 11),through partially masking substrate 50 (FIG. 12), to completely closed(FIG. 13). The iris mechanism is preferably computer controlled; thesize of the iris may be adjusted, even while deposition is proceeding,to provide precise control of the deposition characteristics, includingbut not limited to the rate of deposition, the deposition thickness, andthe variance in deposition thickness. Other variable aperture means maybe utilized instead.

[0067] A preferred embodiment of the iris mechanism aperture 18 of thepresent invention comprises at least three paddles 54(a)-(c), preferablyconnected via posts protruding through the cell via an o-ring sealedport to belt 22 driven by stepper motor 20 that articulates the paddlesin unison so that they close down to a desired aperture size, therebyreducing the open area of substrate 50 mounted on the cathode. Any typeof motor or actuator may be used instead of stepper motor 20.Optionally, more paddles 54 may be used, making the opening in aperture18 more circular.

[0068] The variable aperture also enhances the ability of the presentinvention to plate submicron structures, such as wafer interconnects.Because these structures give rise to highly nonuniform currentdensities, successful plating requires extremely precise platingparameter control. Along with pressurizing the cell, varying theaperture size provides this control so that the structures are uniformlyplated regardless of the line width, pitch, or density of the pattern.

[0069] Also, different wafer designs require different optimal settingsof the aperture size due to differences in the total metallization areaand distribution and density of features to be plated. The variable sizeaperture allows the user to precisely optimize the system for each waferdesign. And an adjustable aperture means that the user does not have toreplace the aperture for each separate wafer design.

[0070] The present invention is also of a dynamic profile anode 100 thatmay be used for plating, electroplating, electrodeposition, chemical andmechanical polishing (CMP), electropolishing, etching, electrolysis, orany other electrochemical process. Although shaped anodes are known inthe art, the present invention is of an anode whose profile can bemodified before or even during processing. Examples of profiles includebut are not limited to flat, convex, domed, curved, hemispherical,conical, pyramidal, or any combination thereof. The shape used will bedetermined through experimentation and optimized for various types ofwafer patterns. For example, conical-type shapes concentrate the ioniccurrent toward the center of the substrate or cathode, thereby providingan additional method of maximizing the uniformity of the depositthickness across the substrate.

[0071]FIG. 14 shows one embodiment of the anode assembly, with anexploded view in FIG. 15 and a cross section in FIG. 16. The assemblycomprises anode 100, which is seated in anode diaphragm 110. Filter 120,preferably cloth or polypropylene, allows ions to pass but preventscontamination from soluble metallic plating media in basket 130 fromreaching anode 100 and eventually the cathode. Basket 130, whichpreferably comprises titanium or another non-soluble metal, is connectedvia contact rods 140 to base 150.

[0072]FIGS. 17 and 18 detail the construction of anode 100. Anode 100 iscomprised of tubes 102 which form a stack up which provides the shape ofthe surface profile of anode 100, and clamp ring 104 which secures tubes102 in place so it is dimensionally stable once the desired surfaceprofile is achieved. Contact bus plates 160 conduct electrical currentto anode 100.

[0073] Another embodiment of dynamic profile anode 100 is shown in FIGS.19-22. FIG. 19 is a cross section view showing a flat surface profile.Current is provided from positive terminal 42 through o-ring seals 170to basket 130, clamp ring 104 and tubes 102. FIG. 20 depicts a convexsurface profile, while FIGS. 21 and 22 show a cross section view andisometric view, respectively, of anode 100 with a conical surfaceprofile. The surface profile may be changed by removing clamp ring 104,adjusting tubes 102 until the desired profile is achieved, and thenengaging clamp ring 104 to hold tubes 102 in place.

[0074] Anode 100 is preferably removable or serviceable, accommodatingthe use of either soluble or insoluble materials to deposit onto thesurface of the wafer. Anode 100 may optionally comprise a solublematerial which dissolves during processing. Preferably, anode 100 may beplatinumized, or be otherwise insoluble. Unlike the prior art, the useof hollow tubes 102 allows a metallic ion source, for example shot,chunks, rings, plates or bars of a desired anode metal or alloy, whichis preferable to a metal salt solution, to be placed in basket 130behind the anode. But because anode 100 is itself insoluble, it retainsthe exact desired shape throughout the deposition process. Thiscombination permits anode 100 to be placed very close to substrate 50.Typical prior art systems require the distance between the anode andcathode to be at least 10 cm. While allowing for any distance, the anodedesign of the present invention permits anode 100 to be situated at adistance from substrate 50 of less than 5 cm, more preferably less than1 cm, and most preferably less than 0.5 cm. The ability to utilize sucha short distance greatly improves the control of the deposition, whichenhances the uniformity of deposit across substrate 50. In addition, ashorter path for the ions to flow to the cathode means thatcontamination of substrate 50 with other ions in solution, or ions froma metallic component in the bath, is drastically reduced.

[0075] Anode 100 of the present invention thus provides for the use ofsoluble metallic anodic materials but does not change its surfaceprofile due to the corrosion of the anodic material during deposition,unlike anodes known in the art. However, if desired, the user maycontrollably vary the surface profile of anode 100 in order to obtain ashape that optimizes the deposition process. This ability to modify theanode's shape as desired, while at the same time retaining the desiredshape (i.e. preventing corrosion) during use of such soluble metallicmaterials, is novel.

[0076] In the present application the system preferably injects theelectroplating solution directly into the anode basket 130 in order tohelp promote the convection of the electron flow carrying the ion matterfrom the anode into the cell's process area. In addition, it ispreferable that the pressure at anode 100 is less than the pressure atsubstrate 50, or cathode, so no countercurrents develop which mightdisrupt laminar flow of the electrolyte adjacent to the substrate 50.

[0077] In addition to the being operated as a single cell or a dedicatedcell for a specific chemical operation, the present invention may beused as a multiple process cell. A first plating solution is introducedinto the cell and a first operation is performed. The first platingsolution may then be rapidly drained, and a rinsing chemistry ispreferably circulated throughout the cell. The rinsing step may berepeated for a number of cycles to achieve a desired level of purity ofthe rinsed wafer surface. Subsequent chemical processes may then beperformed to deposit additional electroplated films or multiplecompositions. For example, a substrate may be plated with a nickel filmover a copper film and followed by a tin film. Or ceramic panels used inthick film type packaging, which require multiple layer film formation,can be produced. Because the system is preferably closed and filtered,clean room conditions with little contamination can be maintainedthroughout the entire multiple operation process. This feature is alsofacilitated by the adjustable aperture and dynamic profile anode, whichallows the user to choose the optimal iris size (or sizes) and anodeprofile for a particular process without having to open the cell andreplace the aperture.

[0078] Optionally the chuck may be magnetic, which allows for magneticparticle codeposition. This process is more fully described in U.S.Provisional patent application Ser. No. 60/519,813, entitled “ParticleCoelectrodeposition”, and U.S. patent application Ser. No. 10/728,636,entitled “Coated and Magnetic Particles and Applications Thereof”. Oneexample of such a chuck is the back seal electrolytic vacuum chuck,disclosed in U.S. Provisional patent application Attorney Docket No.31248-5, entitled “Pressurized Autocatalytic Vessel and Vacuum Chuck”,filed on Feb. 4, 2004. The specifications and claims of these referencesare incorporated herein by reference. One embodiment of such a chuck isshown in FIG. 23, which is identical to FIG. 8 except that it includeselectromagnet 70. The magnetic field may be provided by an electromagnetas depicted, or alternatively a permanent magnet, an array of magnets,or the like. The presence of the magnetic field allows magneticparticles to be codeposited on substrate 50 in a highly controlledmanner before, during, or after the deposition of the electrolyticplating, providing numerous chemical, material, and mechanicaladvantages to the deposited structures.

[0079]FIG. 24 depicts a schematic and flow diagram of a preferredembodiment of a codeposition tool and process. Pump 290 pumpselectrolyte stored in tank 264 to mixer 320, where it is mixed with aslurry of magnetic particles in suspension which was pumped from slurrytank 300 by slurry pump 310. The suspension-electrolyte mixture enterscell 10 and proceeds upward in laminar flow to the codeposition areacomprising anode 100 and substrate 50. Substrate 50 preferably rotatesvia motor 58. Electromagnet 70 attracts magnetic particles from thesuspension-electrolyte so that they are codeposited on substrate 50along with the electrochemical deposition. Controller 230 controlsdeposition parameters, such as the electrode voltage via DC power supply200 and the concentration of magnetic particles in thesuspension-electrolyte mixture via slurry pump 310.

[0080] Waste suspension-electrolyte mixture exits cell 10 throughpressure valve 38. Magnetic separator 240 strips out excess particlesfrom the suspension-electrolyte mixture via an adjustable magnetic fieldprovided by DC separator power supply 242. Nonmagnetic particles andsediments are filtered out using rotary filter 250 and cartridge filter260, although other types of filters may be used. The filteredelectrolyte is then recirculated back into tank 264, where it is cooledvia heat exchanger 270 controlled by temperature control 280. Theelectrolyte may thus be recycled, providing substantial cost savings.

[0081] Although the invention has been described in detail withparticular reference to these preferred embodiments, other embodimentscan achieve the same results. Variations and modifications of thepresent invention will be obvious to those skilled in the art and it isintended to cover all such modifications and equivalents. The entiredisclosures of all patents and publications cited above are herebyincorporated by reference.

What is claimed is:
 1. An apparatus for electrochemical deposition on asubstrate, said apparatus comprising: an anode; a cathode with avertical mounting surface; a pressurized cell to contain electrolyticsolution; and an aperture disposed between said anode and said cathode;wherein a vertical flow of said electrolytic solution is substantiallylaminar in a vicinity of said cathode.
 2. The apparatus of claim 1further comprising a reservoir.
 3. The apparatus of claim 2 wherein thereservoir and cell comprise a closed system.
 4. The apparatus of claim 2further comprising at least one filter.
 5. The apparatus of claim 4wherein at least one of said at least one filter is a submicron filter.6. The apparatus of claim 1 wherein the substrate comprises asemiconductor wafer.
 7. The apparatus of claim 6 wherein the wafer iscoated so that only certain features on the wafer receive thedeposition.
 8. The apparatus of claim 7 wherein said features aresubmicron features.
 9. The apparatus of claim 1 wherein the cell ispressurized to at least approximately one atmosphere above ambientpressure.
 10. The apparatus of claim 9 wherein the cell is pressurizedto at least approximately two atmospheres above ambient pressure. 11.The apparatus of claim 1 wherein said cathode rotates about a horizontalaxis perpendicular to said mounting surface.
 12. The apparatus of claim1 wherein said cell has a geometry that facilitates said laminar flow.13. The apparatus of claim 12 wherein said cell comprises an invertedtriangular or conical shape in a vicinity of an electrolyte inlet port.14. The apparatus of claim 12 wherein said cell is of sufficient heightto ensure that said flow is laminar in a vicinity of said cathode. 15.The apparatus of claim 1 wherein said aperture is electricallyinsulating.
 16. The apparatus of claim 1 wherein said aperture comprisesan opening.
 17. The apparatus of claim 16 wherein said opening iscircular.
 18. The apparatus of claim 16 wherein a size of said openingis variable.
 19. The apparatus of claim 18 wherein the size of saidopening may be varied during operation of the cell.
 20. The apparatus ofclaim 18 wherein said aperture comprises an iris.
 21. The apparatus ofclaim 20 wherein said iris comprises at least three paddles.
 22. Theapparatus of claim 18 wherein the size of said opening is larger than asize of the substrate.
 23. The apparatus of claim 18 wherein saidopening can be completely closed.
 24. The apparatus of claim 1 whereinsaid anode is situated less than approximately 5 cm from said cathode.25. The apparatus of claim 24 wherein said anode is situated less thanapproximately 1 cm from said cathode.
 26. The apparatus of claim 25wherein said anode is situated less than approximately 0.5 cm from saidcathode.
 27. The apparatus of claim 1 wherein a metal ion source issituated behind said anode, thereby minimizing contamination fromreaching the substrate while said anode retains a constant surfaceprofile.
 28. The apparatus of claim 1 wherein a surface profile of saidanode is controllably variable.
 29. The apparatus of claim 28 whereinsaid surface profile can be varied during operation of said cell. 30.The apparatus of claim 28 wherein said anode comprises parallel hollowelectrically conducting tubes.
 31. The apparatus of claim 1 furthercomprising a magnet.
 32. The apparatus of claim 31 wherein said magnetcomprises an electromagnet.
 33. The apparatus of claim 31 wherein saidmagnet comprises at least one permanent magnet.
 34. The apparatus ofclaim 31 wherein said magnet provides for codeposition of magneticparticles with electrochemical deposition on the substrate.
 35. Theapparatus of claim 34 wherein a strength of said magnet is adjusted toprovide a desired concentration of magnetic particles on the substrate.36. An apparatus for performing multiple electrochemical depositions ona substrate, said apparatus comprising: an anode having a variablesurface profile; a cathode with a vertical mounting surface; apressurized cell to contain electrolytic solution; a closed system forcirculation of the solution; and an aperture with a variably sizedopening disposed between said anode and said cathode; wherein a verticalflow of said electrolytic solution is substantially laminar in avicinity of said cathode.
 37. The apparatus of claim 36 wherein themultiple depositions are carried out without opening said cell betweeneach deposition.
 38. The apparatus of claim 36 wherein said surfaceprofile of said anode is controllably varied as desired for eachdeposition.
 39. The apparatus of claim 36 wherein a size of said openingis varied as desired for each deposition.
 40. The apparatus of claim 36further comprising a filter.
 41. A method of electrolytically depositinga material on a substrate, the method comprising the steps of: providingan electrolytic cell; providing an anode; mounting the substrate on acathode so that a surface of the substrate is vertically disposed;disposing an aperture between the anode and cathode; providing laminarflow of electrolyte solution through a cell; pressurizing the solutionto a desired pressure; and providing an electric potential differencebetween the cathode and the anode.
 42. The method of claim 41 whereinthe step of providing laminar flow comprises filtering the solution. 43.The method of claim 41 further comprising the step of uniformly platingsubmicron features on the substrate.
 44. The method of claim 41 whereinthe mounting step further comprises rotating the substrate about ahorizontal axis perpendicular to the surface.
 45. The method of claim 41wherein the disposing step further comprises varying a size of anopening of the aperture.
 46. The method of claim 41 wherein the step ofproviding an anode comprises situating the anode less than approximately5 cm from the cathode.
 47. The method of claim 46 wherein the step ofproviding an anode comprises situating the anode less than approximately1 cm from the cathode.
 48. The method of claim 47 wherein the step ofproviding an anode comprises situating the anode less than approximately0.5 cm from the cathode.
 49. The method of claim 41 wherein the step ofproviding an anode comprises situating the anode between a metallic ionsource and the cathode.
 50. The method of claim 49 wherein the step ofproviding an anode comprises minimizing contamination from reaching thecathode while retaining a constant surface profile.
 51. The method ofclaim 41 wherein the step of providing an anode comprises controllablyvarying a surface profile of the anode.
 52. The method of claim 41wherein the mounting step further comprises providing a magnetic field.53. The method of claim 52 further comprising the step of using themagnetic field to codeposit magnetic particles with the material on thesubstrate.
 54. The method of claim 53 further comprising varying themagnetic field to adjust the composition of the magnetic particles onthe substrate.
 55. A method of performing multiple electrolyticdepositions on a substrate, the method comprising the steps of: a.providing a pressurized electrolytic cell; b. providing an aperture witha variably sized opening; c. optimizing deposition parameters of thecell including a pressure of the cell and a size of the opening for adesired deposition; d. depositing a material on a substrate; and e.repeating steps (a) through (d) without opening the cell.
 56. An anodefor use in an electrochemical process, said anode comprising: aplurality of parallel hollow electrically conducting tubes with sides inslideable contact with one another; and a clamp circumferentiallydisposed around the plurality of tubes to prevent motion of the tubes.57. The anode of claim 56 wherein the tubes are cylindrical.
 58. Theanode of claim 56 wherein the tubes have a cross section comprising aregular polygon.
 59. The anode of claim 56 wherein a surface profile ofthe anode comprises positions of ends of each of the tubes which face acathode.
 60. The anode of claim 59 wherein the surface profile isadjustable by sliding the tubes relative to one another.
 61. The anodeof claim 56 wherein a shape of the surface profile is selected from thegroup consisting of flat, convex, hemispherical, conical, domed, curved,and pyramidal.
 62. The anode of claim 56 comprising an electricallyconducting material.
 63. The anode of claim 56 comprising a solublematerial.
 64. The anode of claim 56 comprising an insoluble material.65. The anode of claim 64 comprising a platinumized material.
 66. Theanode of claim 56 further comprising a receptacle for placement of anelectrochemical ionic source media.
 67. The anode of claim 66 whereinthe media is a metallic ion source.
 68. The anode of claim 66 whereinthe receptacle is on a side of the anode opposite the surface profile.69. The anode of claim 68 wherein the anode minimizes contamination fromreaching a cathode while retaining a constant surface profile.
 70. Theanode of claim 56 wherein the process is selected from the groupconsisting of plating, electroplating, electrodeposition, chemical andmechanical polishing (CMP), electropolishing, etching, and electrolysis.